The Tory Government has been warned that it faces a court battle if it goes ahead with Brexit talks without first giving Parliament a say.
A group of unnamed businesses have instructed leading London law firm Mishcon de Reya to take pre-emptive legal action to ensure MPs and peers have a veto over the formal exit of the UK from the EU.
In what pro-EU campaigners hope is a last ditch move to delay or even stop Brexit, the solicitors have warned Government lawyers that they will take action if ‘Article 50’ of the European Union Treaty is triggered by the Prime Minister without new Act of Parliament.
The legal threat, which infuriated some Tory Eurosceptics, came as each of the contenders to replace David Cameron suggested different timetables for starting the formal process of leaving the EU.
Andrea Leadsom, now seen as the first choice of many ‘Leave’ MPs, said on Sunday that she would trigger Article 50 immediately on becoming PM, after the Tory leadership election in September.
Overall frontrunner Theresa May said she would wait until 2017, whereas Michael Gove said he would trigger the legal process by the end of this year if he won the contest.
A majority of MPs in Parliament came out against Brexit before the referendum result, as many Tory MPs backed Cameron in his ‘Remain’ campaign, and there have been calls by MPs such as Labour’s David Lammy to stop Brexit in its tracks.
If a new Prime Minister ‘triggered’ Article 50, they would use powers given them under the Royal Prerogative. But the lawyers claim that only an act of Parliament can override the law that first approved the UK's membership in the 1970s.
Mishcon de Reya said it had retained the services of senior constitutional barristers, including Lord Pannick QC and Rhodri Thompson QC, to put its case. Their clients said to be a ‘small but growing’ group of businesses and academics.
A statement by the firm said that it was not questioning the result of the EU referendum but it claimed it was “not legally binding” and needed a UK law to enshrine it.
The legal action appears to exploit the ambiguous wording of Article 50 of the Treaty on European Union, which sets out how states could leave the EU.
The first clause declares: “Any member state may decide to withdraw from the Union in accordance with its own constitutional requirements.”
Kasra Nouroozi, a partner at Mishcon de Reya, said: “We must ensure that the government follows the correct process to have legal certainty and protect the UK constitution and the sovereignty of parliament in these unprecedented circumstances.
“The result of the referendum is not in doubt, but we need a process that follows UK law to enact it. The outcome of the referendum itself is not legally binding and for the current or future prime minister to invoke article 50 without the approval of parliament is unlawful.
“We must make sure this is done properly for the benefit of all UK citizens. Article 50 simply cannot be invoked without a full debate and vote in parliament. Everyone in Britain needs the government to apply the correct constitutional process and allow parliament to fulfil its democratic duty, which is to take into account the results of the referendum along with other factors and make the ultimate decision.”
Tory MP Kwasi Kwarteng said the law firm’s manoeuvre was “outrageous and incredibly arrogant”, adding “these people are just grandstanding”.
Ukip MP Douglas Carswell told City A.M.: “I suspect this will confirm the worst fears of many of millions of people who fear the establishment trying to subvert the outcome of the referendum. If, as a result of lawyers, the clear majority view was subverted, then god help us, we would go into an extremely dangerous situation.”
Bernard Jenkin, who chairs parliament’s Public Administration and Constitutional Affairs Committee, added: “This is an extraordinary attempt to disrupt the consequence of a referendum... We have a democracy, the democracy is working fine and we don’t need the judges to intervene with it.”
But leading Brexiteers Lord Lawson and Lord Owen wrote in CityAM that they wanted the new PM to introduce an act of Parliament before Christmas to trigger Article 50.
“The new Prime Minister should have this legislation drafted and presented to Parliament immediately, so it can be enacted and ready to bring into force when needed. This should be on the Statute Book before the Christmas recess,” they said.